Human Papillomavirus (HPV) is known cause of cervical cancer in woman but it can also cause penile, anal, vulvar, vaginal and orophanryngial cancers (Forman et al. 2012, Vaccine). Two prophylactic L1 protein virus-like particles (VLPs) based vaccines have been shown to prevent infection with the high risk cancerogenic HPV 16 and 18 types (Schiller et al. 2012, Vaccine). One of these also provides protection against HPV 6 and 11 types (Schiller et al. 2012, Vaccine).
Although these vaccines are highly effective at preventing HPV 16 and 18 infections, which cause approximately 70% of the cervical cancer cases worldwide, 13 other HPV types are known to be cancerogenic as well. In descending order of importance, genotypes HPV 45, HPV 31, HPV 33, HPV 52, HPV 58, HPV 35, HPV 56, HPV 51, HPV 39, HPV 68, HPV 73 and HPV 82 cause the remaining 30% of the worldwide reported cervical cancer cases (Hanna Seitz, 2014)). To ensure protection against the less prevalent HPV types, a nine-valent L1 VLP based vaccine has been developed which in addition to the HPV 6, 11, 16 and 18, also aims at providing protection against the HPV types 31, 33, 45, 52 and 58 (Munoz et al., 2004; Smith et al., 2007). Despite the effective prevention against infections from the mentioned genotypes, L1 VLP based vaccines offer limited cross-protection and they are also very expensive to manufacture. This prevents their global implementation, in particular in the developing world where ˜80% of the HPV cases occur (Parkin & Bray, 2006; Schiller & Lowy, 2012). Hence, there is a need for immunogenic vaccines that are (cross-) protective against many HPV types.